Static-potential-controlling apparatus



June 3, 1 24. 1,496,755

R. M. GILSON STATIC POTENTIAL CONTROLLING APPARATUS I Original FiledJune 14, 1919 INVENTOR 4 BYQ A Q. ATTORNEY Patented June 3, 1924.

UNITED STATES PATENT OFFICE.

ROBERT Original application filed June 14, 1919, Serial No. 304,308.

M. GILSON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWISSVALE.PENNSYLVANIA, A CORPORATION OF STATI C-POTENTIAL -CON TR-OLLIN GAPPARATUS.

To all whom it may concern.

Be it known that I, Bonner M. GrLsoN,

a citizen of the Pittsburgh,

State of tam new United States, residing at in the county of Alleghenyand Pennsylvania, have invented cerand useful Improvements inStatic-Potential-Controlling Apparatus, of

which the following is a specification.

invention relates to static potential controlling apparatus, andparticularly to apparatus for controlling the potential applied tocurrent-consuming devices which are known to be lilnited as to life.devlces may,

Such for example, be electric lamps,

tungar rectifiers, or other devices comprising heated filaments,although I do not wish to be limited to any particular character ofcurrent-consuming device.

One object of my invention is the provision of means havingno contactsor other moving arts for lacin a reserve currentconsuming device inservice when a device which has previously been in service ceases tofunction.

The present application is a division of my copending 308, for statictus, filed 1,449,987, 1923.

application Serial No. 304,- potential controlling appara- June 1 1,1919, now'Patent No.

issued on the 27th day of March I will describe one form of apparatusembodying my invention, and will then point character secondarydesignates a transformer, the of which is connected with acurrent-consuming device L, which, as here shown, is an incandescentlamp. This lamp L will be hereinafter referred to as the main lamp. Theprimary of the transformer T rent by suitable of a transformer T nectedwith a source is supplied with alternating curmeans, such as thesecondary whose primary is con of alternating current which is not shownin the drawing. Suitable means are provided for limiting the amount ofcurrent supplied to transformer T, this means as here actance R formers.

shown being a reinterposed between the two trans- A reservecurrent-consuming delamp when hot, is, ofcourse 50 the transformer Tvice L lamp, is the primary of transformer T.

The parts of the apparatus shown in Fig. 1 may be so proportioned thatwhile lamp L is burning at normal voltage the voltage applied to thereserve lamp L is considerably below normal, but that when lamp L burnsout, the voltage applied to lamp L will be increased to the normal valueso that this lamp will then burn at normal brilliancy. As an example. Ihave found that this result may be attained by proportioning the partsas follows:

I will assume that each lamp L and L is of the tungsten filament typeand that these lamps are of about two candle power, taking .2 ampere at10 volts, lamps of this type and size being the ones which arecustomarily used for semaphore lighting in railway signaling. Theresistance of each ohms. If is made with a 1 2 ratio,

also in the form of an incandescent therefore, which equals .13 ampere.I

will, furthermore, assume that the exciting current for transformer T is20% of the local current, that is, .08 ampere at .4 power factor, andthat this exciting current increases in proportion to the appliedvoltage. It will be found by computation, or by the construction of avector diagram, that the total current flowing in reactance R is thenabout .56 ampere. I will assume that the power factor of the reactance Ris .1 and that the value of this reactance is about 23 ohms. If thepotential at the secondary of transformer T is 15 volts, the result willbe a potential of 10 volts across lamp L, while this lamp is burning.

When lamp L burns out, there will be a potential of 15 volts applied toa cir- Divided and this application filed February 7 Serial No.620,790."

connected across the terminals of of the secondary is 10 cuit composedof the reactanceR in series with ,an impedance composed 'oflamp L? andthe primary of transformer T in multiple. Assuming that lamp L now burnsat 10 volts, its resistance will be ohms at unity power factor. Theimpedance of the pri mary of transformer T is which equals 62.5 ohms at.4 power factor. To combine these two impedances in multipleitisnecessary to determine the admittancesofeach branch. The admittance ofthe lamp L is Theadmittance of" the primary: of transformer T is Ycompntation or by vector diagram it will be found that the combinedadmittance of .these two im'pedances isLOB', at an angle'of .29 de ees.The combined impedance of lamp 2. and the primary of transformer T istherefore this impedance also being at: an angle of 29v degrees. To

this .must be. added the vimpedance. of the coil R (23 ohmsxat .1

power factor). The total impedance in the circuit will then'be foundtosbe about 50 .ohms. The current .fiowingin the circuit is thereforeampere.

It follows that. the-potentialv across lamp 7 L limit myself and acrossthe primary oftransformerT' is .'Q31 33;3:1O volts, which is-thedesired'voltage at this lamp after lamp Lburns out.

Although in describing in detail the operation and structure of theapparatusemmyinvention, I have referred to b'Odying thecurrent-consuming devices as incandescent lamps,

and haveso illustrated them in the drawings,

to devices of this particular it isunderstood that I do not type. Anycurrent-consuming device or devices mayv be substituted for the lampsshown in the drawing.

Although I have herein shown and described only oneform and arrangementof apparatus embodying my invention, it is understood that variouschanges and modi- V ficationsmay bemade therein within the scope of theappended claims without departing from the spirit and scope .of myinvention.

Having thus described my invention, what I claim is:

1. Static potential controlling apparatus comprising a transformer, amain currentconsuming device connected with the secondary thereof, areserve current-consumlng device connected across the-secondary thereof,a'reserve current consuming deviceconnected across'the primary of saidtransformer, and means for limiting the amoimt of current flowing in theprimary of said transformer. I

4. Static potential controlling apparatus comprising a transformer, amain currentconsuming'device connected with the secondary thereof, areserve current-consuming device connected across theprimary of saidtransformer, and a reactance connected'in serieswith the primary of saidtransformer,

the rparts'being; so proportioned that when themain device isgconsumingcurrent the potential applied thereto, is the normal operating value andthe potential applied to the reserve device is considerably below thenormal operating value, but that when the main device is not consumingcurrent the potential applied to the reserve device rises to the normaloperating value of the device.

In testimony whereof I aflix m signature.

' ROBERT M. ILSON.

flowing to the primary

